The present invention generally relates to an electric circuit construction, and more particularly, to a connecting structure of four diodes on a substrate in a double-balanced mixer employed, for example, in a CATV (cable television) tuner and the like.
Conventionally, in a double-balanced mixer as referred to above, it has been a practice to connect four diodes D1, D2, D3 and D4 in a bridge connection between ports PA and PB on a substrate (not shown) in an arrangement as shown, for example, in FIG. 5.
In the known arrangement as described above, however, since the diodes D2 and D4 inevitably intersect each other, either one of the diodes D2 or D4 must be disposed on the other side face (e.g., on the reverse side face) of the substrate, and therefore, there have been problems in that (1) due to the necessity for fixing the diodes on both side faces of the substrate, extra procedures are required to achieve the fixing, and (2) even if it is intended to subject the reverse side face of the substrate to immersion in solder, such treatment can not be effected since the diode on the reverse side face would be undesirably immersed in the solder.